Perhaps you should try some spelling variations:
11.4.1 communication » 10.4.3 communication, 12.4.4 communication, 13.4.5 communication
population level » population center, population age, population based
developpement l » developpement il, developpement la, developpement de
primer 11.4.1 » primer 11.1.1, primary 11.1.1, crimes 1.4.1
technology 2 » technology _, technology 1, technology 3
level primer » level price, level pre, el primer
l afrique » en afrique

You may be able to get more results by adjusting your search query.

• Adding a wildcard symbol may retrieve word variants: technology 2 population level primer 11.4.1 communication costs _ developpement l afrique.*.